6533b7d0fe1ef96bd125a3c4
RESEARCH PRODUCT
HELMINTH ASSEMBLAGES OF WHITEFISH (COREGONUS LAVARETUS) IN INTERCONNECTED LAKES: SIMILARITY AS A FUNCTION OF SPECIES SPECIFIC PARASITES AND GEOGRAPHICAL SEPARATION
E. Tellervo ValtonenAnssi Karvonensubject
Biotopefood.dishEcologyZoologyFresh WaterBiologybiology.organism_classificationGeneralist and specialist speciesFish DiseasesfoodSpecies SpecificityCoregonus lavaretusGeographical distanceHelminthsFreshwater fishAnimalsRegression AnalysisParasite hostingDominance (ecology)ParasitologyHelminthiasis AnimalFinlandSalmonidaeEcology Evolution Behavior and SystematicsTrophic leveldescription
This article examined the composition of parasite assemblages of whitefish (Coregonus lavaretus) in 8 interconnected lakes in northeastern Finland and evaluated the role of coregonid specific parasites and the geographical distance between populations in determining the similarity of the assemblages. Parasite assemblages were compared using the Jaccard qualitative similarity index and a quantitative similarity index and by incorporating the allogenic-autogenic species concept and the effects of 2 corresponding measures of geographical distance between the lakes. The majority of the parasite species found (10 of 14) were specific to salmonids. Similarity of assemblages of autogenic parasites between the lakes was negatively correlated with geographical distance. The dominance of 2 parasite species, the whitefish specialist Ichthyocotylurus erraticusand the generalist Ergasilus sieboldi, was also demonstrated. We concluded that the high proportion of widespread parasite species specific to coregonids is an important determinant of similarity in these assemblages. However, ecological factors were likely to contribute to qualitative (presence of species) and quantitative (difference in abundances) differences between lakes, in the case of autogenic parasites, their importance increasing with geographical separation. The determinants of similarity between the parasite assem- blages of freshwater fish from different host populations has been 1 of the major questions in parasite ecology in recent years. Several studies have supported the view that parasite as- semblages are structured by factors that lead to a predictable species composition (e.g., Halvorsen, 1971; Wootten, 1973; Hartvigsen, 1995). In contrast, studies in Britain have supported the stochastic nature of these assemblages, emphasizing the sig- nificance of individual characteristics of lakes as well as chance colonization and infection events (Kennedy, 1978, 1990; Esch et al., 1988; Hartvigsen and Kennedy, 1993). Factors affecting parasite assemblages of freshwater fish are undoubtedly numerous, e.g., lake size, altitude, trophic status, etc. (e.g., Wisniewski, 1958; Chubb, 1970; Esch, 1971; Ken- nedy, 1978; Esch et al., 1988; Marcogliese and Cone, 1991). However, recent studies have emphasized the role of wide- spread parasites species and the geographical distance between populations determining the similarity of parasite assemblages (Kennedy and Bush, 1994; Choudhury and Dick, 1998; Poulin and Morand, 1999). First, if parasite assemblages of 1 particular host species are dominated by highly widespread parasites, these species are likely to be found in majority of populations thus promoting similarity between populations. Choudhury and Dick (1998) studied the parasite assemblages of sturgeons and found that the species composition was dominated by wide- spread specific parasites. They stressed the role of persistent composition of specific parasites species in determining the pre- dictability in their study system and throughout the distribution area of acipenserid fish. However, Choudhury and Dick (1998) also noted that exceptions to this pattern might rise, for ex- ample, through exchanges of nonspecific parasites with other host species (see also Leong and Holmes, 1981).
year | journal | country | edition | language |
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2004-07-24 | Journal of Parasitology |